Resumen: Excellent energy resolution is one of the primary advantages of electroluminescent high-pressure xenon TPCs. These detectors are promising tools in searching for rare physics events, such as neutrinoless double-beta decay (ßß0¿), which require precise energy measurements. Using the NEXT-White detector, developed by the NEXT (Neutrino Experiment with a Xenon TPC) collaboration, we show for the first time that an energy resolution of 1% FWHM can be achieved at 2.6 MeV, establishing the present technology as the one with the best energy resolution of all xenon detectors for ßß0¿ searches. [Figure not available: see fulltext. Idioma: Inglés DOI: 10.1007/JHEP10(2019)230 Año: 2019 Publicado en: Journal of High Energy Physics 2019, 10 (2019), 230 1-11 ISSN: 1126-6708 Factor impacto JCR: 5.875 (2019) Categ. JCR: PHYSICS, PARTICLES & FIELDS rank: 4 / 29 = 0.138 (2019) - Q1 - T1 Factor impacto SCIMAGO: 0.948 - Nuclear and High Energy Physics (Q2)